I already have a 200R quad pot I would like to make use of in a preamp I am building since quad pots are not trivial to source. The op amp driving aginst the pot is an OPA1632. I don't see a problem, as the OPA should be able to drive this load and the amp should work fine with a lower-Z input. Is this acceptable? I do have room to increase the gain on the OPA, and I was considering doing that and maybe putting 400R in series with the pot to bring it up to a nominal 600R. Is that worth the effort?
Hi leadbelly,
I was waiting for someone to give you a reply. I don't believe this is a good idea for the simple reason that you are making life hard for the op amp. Just because they can handle, say, a 600 ohm load does not mean you should. Distortion almost always increases with decreasing load impedance. You are increasing the dynamic impedance seen by the amplifier.
You would be further ahead to use your quad 200 ohm control for something else.
-Chris
I was waiting for someone to give you a reply. I don't believe this is a good idea for the simple reason that you are making life hard for the op amp. Just because they can handle, say, a 600 ohm load does not mean you should. Distortion almost always increases with decreasing load impedance. You are increasing the dynamic impedance seen by the amplifier.
You would be further ahead to use your quad 200 ohm control for something else.
-Chris
anatech said:
I need it for a balanced phono stage: http://www.diyaudio.com/forums/showthread.php?s=&threadid=73110
I can make do with a dual gang but prefer not to compromise. I'm handy enough to cobble up something that should track well, at least I hope I am
A couple of quad gang pots came my way in a mess of goodies that a gentleman moving out of the country gave me. All low grade electronics, lots of stuff from India, but occasionally I find something useful in there.
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